Major Ralph "Pappy" Shelton, who has died aged 80, was the American officer who trained the Bolivian troops that captured Che Guevara in 1967. Together with 16 Spanish-speaking US officers, Shelton set up a training camp in eastern Bolivia in April 1967 to teach a battalion of 400 Bolivian conscripts the techniques of counter-guerrilla warfare. When their training ended in mid-September, they were transferred to the guerrilla zone, and two weeks later, on 8 October, surrounded Guevara's guerrilla band. Guevara himself was wounded and captured, and executed on 9 October. Shelton slipped out of the country on the following day and returned to his headquarters in the Panama Canal Zone.

"We had a job to do and we did it," Shelton said last year. "The people of Bolivia wanted Guevara gone and asked for help, and we were glad to give it. That man is famous now, but he killed lots of innocent people and we were glad to help put him out of business."

Shelton was the son of a poor farmer who moved from Mississippi to Tennessee. He contributed to the family income by working as a logger and sawmill operator before leaving for Detroit aged 17 to find work in an automobile plant. He joined the army in 1948 and was sent initially to Japan before serving as a sergeant in the Korean war. He was wounded and returned to his father's farm but, unimpressed by the farming life, returned to the army. He served in Germany and then went to an officers' training school, graduating first in his class as a second lieutenant. As the oldest trainee, he acquired the nickname "Pappy".

In 1962, aged 32, he joined the elite "special forces", or Green Berets, established by the Kennedy government in 1961 to combat guerrilla insurgencies in different parts of the world. Shelton was sent out to Laos where the Green Berets operated behind enemy lines in the fight against the Pathet Lao guerrillas. After Spanish-language training in the Panama Canal Zone, Shelton was dispatched to the Dominican Republic in the wake of the US invasion in 1965 as part of the mobile training teams (MTTs) that the US military was setting up to assist local armies. In March 1967, when news of a guerrilla uprising in Bolivia first surfaced, Shelton was the obvious candidate to lead the MTT for deployment there.

Shelton flew to Bolivia in April and, in collaboration with Colonel Joaquín Zenteno Anaya, the Bolivian commander in the guerrilla zone, searched for a training base. They found an abandoned sugar mill outside the small settlement of La Esperanza, some 40 miles north of Santa Cruz, and training began. Shelton was in his element: he commandeered the bulldozers being used by an American aid mission, he embarked on civic projects to endear his troops to the locals, and he took little notice of the US ambassador in La Paz or his military superior, Colonel JP Rice, based in Cochabamba. Shelton reported directly to US southern command in Panama, with whom he was in daily radio contact. He was also kept well informed of the guerrilla fighting 100 miles to the south, through two Cuban exiles operating as CIA agents in the field.

When I interviewed Shelton at La Esperanza in October 1967, he was preparing for a training session with a second battalion of conscripts, but he seemed confident that the guerrilla war was ending. The next day, a sergeant from the US camp, sitting at his favourite cafe in the main square, jumped up to tell me that Guevara had been captured. When I bumped into Shelton at the airport two days later, he gave a smile but said nothing, except: "Mission accomplished."

Shelton retired from the army after his Bolivian excursion and took a master's degree at the University of Memphis. An active public servant, a mason and a board member of his Methodist church, he also served as a commissioner in the mayor's office in Sweetwater, Tennessee. He is survived by his wife, Susan, and four daughters.

•Ralph "Pappy" Shelton, US counter-insurgency officer, born 1930, died 29 June 2010